Coral Health and Disease in the Pacific: Vision for Action

What have we learned from Caribbean coral disease research?Research on coral diseases requires an approach that combines ecologicalmonitoring with biochemistry, molecular biology, histology, toxicology, physicaloceanography, ecology, taxonomy and other laboratory and field methods. Aninterdisciplinary approach is necessary to identify, differentiate and characterize coraldiseases and their consequences, and understand relationships among diseases and otherbiotic and abiotic factors. Epizootiology: To understand the spatial extent of diseases at local to global scales,large areas of reef must be examined at the same time. Surveys must also beconducted at frequencies that are sufficient to document the duration of the condition,and identify seasonal patterns or chronic effects. Monitoring programs should includesize measurements and colony condition (amount of recent and old mortality), andfollow individual colonies over time to determine the severity of disease and potentialpopulation level impacts. Efforts should be made to standardize monitoringapproaches. Relationships between disease outbreaks and environmental factors:Epizootiological studies must be combined with an examination of climateparameters (e.g., temperature and light levels), water quality measures (levels andtypes of nutrients and contaminants, turbidity, and rates of sedimentation), andimpacts of other natural disturbances (e.g., predator outbreaks and hurricanes). Rapid response program: A coordinated rapid response to disease outbreaks canallow for the timely recognition, characterization, and reporting of disease outbreaks.This information is necessary so managers can 1) quickly direct resources toadditional studies that are needed to identify appropriate management responses; 2)identify possible responses to control or mitigate the outbreak and 3) educate localand regional stakeholders on the condition of the corals. Coral disease diagnostics and nomenclature. There is a need to review and refineexisting terminology and develop an approach for naming new diseases to reduceconfusion. Disease nomenclature must include descriptive terminology of the grosssigns (visible by an unaided eye, underwater) that could be applied by all scientistsconducting epizootiological studies. Lesions should first be categorized as tissueloss, growth anomaly, and/or change in coloration. For each lesion, relevantinformation on the distribution of the lesions (e.g., focal or multifocal), location oncolony, lesion shape, relief, texture, color, and size, and structures affected (e.g.tissue, individual polyps, coenosarc, skeleton) should be included in the morphologicdiagnosis. By following affected colonies over time, more detailed information onpatterns and rate of spread and extent of tissue loss can be compiled. This fieldterminology can be further refined once a causative agent is identified. Identification of the causative agents Molecular approaches should be combinedwith traditional culture techniques to identify and verify coral associated microbes,including spatial and temporal fluctuations, variations among species, and differencesbetween healthy and diseased corals. Screening must include larger sample sizes(especially when isolating a putative pathogen and testing infectivity of proposedpathogens), multiple species (if they show similar signs), and multiple locations.There is an urgent need for molecular probes that will allow rapid screening of corals.150